Helix shaped concentrators as outlined in prior art are basically composed of a passive tracking helix shaped semi-tubular reflector which has been spiraled as much as 360 degrees in the form of a helix so as to always expose at least some part of the reflective surface of the sun in order to concentrate radiant solar energy onto an energy absorber collecting core. Such a helix shaped collector-concentrator is described in a concave form in a prior U.S. patent application for a CONCAVE HELIX SOLAR CONCENTRATOR, Ser. No. 934,833, filed Aug. 18, 1978, and in a U.S. disclosure document for a CONCAVE HELIX SOLAR CONCENTRATOR, Ser. No. 072,971, filed July 25, 1978. Such a concentrator as described therein depends upon one core as shown in FIG. 1 of the Ser. No. 934,833 patent application and FIG. 1 of the Ser. No. 072,971 disclosure document. Since the single core is in the exact focal point of the concentrator at all times, only a small area of the collector core is in sharp focus at a particular position of the sun in the sky. The efficiency of the concentrator is lowered because of the small area of sharp focus of the sun's solar energy, additionally primary direct, reflective and non-reflective incident solar energy are not utilized to the fullest degree because of the inherent limitation of only one collecting core.
Further, because of a lack of a covering for both the reflector and collecting core, energy is lost by heat dissipation to the environment. If a wind blows, it also institutes a cooling effect on the collecting cores and on the reflector depending upon the chill factor of the wind and the surrounding temperature of the atmosphere.
In addition, an uncovered helix shaped reflector tends to collect ice and snow in those climates with heavy winter precipitation, especially detrimental to solar energy collection when the sun is obscured during the day by cloud formation. This lack of covering may also leave the reflector and energy absorber collecting cores prone to deterioration by exposure to atmospheric pollutants that exist to some degree and variation in all parts of the world.
Whereas a simple concave configuration to a helix shaped reflector does not make fully efficient use of the reflective surface to concentrate the sun's rays on a central core, a different, more effective compound geometric shape is needed for an efficient helix reflector.
It is therefore an object of this invention to increase radiant solar energy collection of a helix shaped concentrator by providing a plurality of specifically positioned of energy absorber collecting cores exposed to primary direct incidence of the sun's rays, as well as to reflective and non-reflective incident energy collection.
Another object of this invention is to improve the thermal heat energy collecting efficiency of single or multiple energy absorber collecting core helix shaped concentrators by additional means, such as providing a means of covering the helix shaped collector-concentrator with a transparent, relatively air-tight enclosure which is resistant to environmental factors such as snow, wind, rain and atmospheric pollutant degradation. A further object of this invention, through the utilization of the aforementioned transparent, relatively air-tight covering is to increase the energy collection within the energy absorber collecting cores, by trapping and confining the heat energy generated within the helix shaped concentrator and immunizing the helix shaped reflector and its attendant energy absorber collecting core or cores from wind chill and heat dissipation. A further object of this invention is to provide a more effective geometric shape for the helix concentrator's reflective surface besides being simply helix shaped and concave in form.